Field of the Invention
This invention relates to agricultural combines and, more particularly, to a selectively employable extension assembly that can be utilized to increase the effective volume of a storage tank for crop processed by the combine.
Background Art
Extension assemblies have been utilized on access door panels for combine storage tanks for decades. By increasing the capacity of a storage tank for processed crop, farmers are allowed to harvest a larger volume of crop before having to unload to a cart or trailer.
Typically, these extension assemblies have increased the storage tank capacity by adding height to the access door panels when the panels are in an open position. Various designs have evolved with capabilities of increasing effective storage volume to different degrees. Further, the existing extension assemblies have utilized different components and materials, among which are a combination of steel and rubber, steel and canvas, steel and plastic, or steel only.
Generally, the extension assemblies are relatively simple to install and are easy to take apart for combine storage or over-the-road transport. Until recently, combines have had only manually folding OEM door panels that are repositioned to selectively block and expose a top access opening for the storage tank. A recent trend has been to change more to the option of power folding door panels. The farmer then is not required to leave the combine cab and climb on top of the combine to manipulate the door panels. While a convenience and safety improvement, this automated operation does add extra cost to the combine.
By integrating extension assemblies, the automated folding of door panels has been complicated. To avoid interference of multiple interacting panels, volume extension has generally been achieved by using collapsible canvas/rubber extension materials. With this construction, the extensions can fold, as at the corners, to accommodate repositioning panels. These materials deform readily and thus are generally practically designable only to accommodate a limited increase in volume—otherwise risking the possibility of deformation that might allow escape of harvested crop. This deformation may be effected by the weight of the crop or even by strong winds.
One attempted solution to this problem is to use a surrounding cable to maintain the upper diameter of the extension components. However, this cable may preclude automated operation of the primary panels and may interfere with normal combine operation.
Additionally, the canvas/rubber design is generally aesthetically undesirable. This alone may make the use thereof impractical, particularly given the limited increase in volume made possible thereby.
While use of rigid extension panels contributes to greater structural stability, designing rigid panels: a) with sufficient surface area to significantly increase storage volume; and b) that will at the same time be collapsible through a practical mechanism, has presented a particular challenge. Ideally, these extension assemblies are constructed so that their reconfiguration can be coordinated with the automated operation of the main door panels without requiring complicated mechanisms or any manual intervention by an operator.
The industry continues to be in need of better technology that allows significant increase in storage volume in a form that has good structural integrity and is compatible with automated door panel operation.